A foundation composition can be applied to the face and other parts of the body to even skin tone and texture and to hide pores, imperfections, fine lines and the like. A foundation composition is also applied to moisturize the skin, to balance the oil level of the skin and to provide protection against the adverse effects of sunlight, wind and the harsh environment.
Make-up compositions are generally available in the form of liquid or cream suspensions, emulsions, gels, pressed powders or anhydrous oil and wax compositions.
U.S. Pat. No. 3,444,291 discloses a method of filling and camouflaging skin cavities by applying a composition which includes 65 to 75 parts by weight of a microcrystalline wax and about 25 to 35 parts of a mineral oil. The composition includes a colourant, preferably a coal tar dye, for example, D&C Red No. 17, which matches the colour of the user's skin.
A spreadable, flowable and greaseless cosmetic cover-up composition is taught in U.S. Pat. No. 4,486,405. That composition is characterized by the presence of a first and a second alkoxylated surfactant present in substantially the same concentration.
U.S. Pat. No. 4,804,532 recites a facial cosmetic powder which utilizes crystalline silica in much lower concentration than that employed in the then prior art compositions. This powder, used as a blush or a facial coating, is said to be effective in hiding skin wrinkles, lines and pores. The composition is a mixture of a colour phase and a diluent phase. The colour phase is formed by blending crystalline silica with colourants. The resultant colour phase is mixed with the diluent phase, essentially formed from nacreous materials such as talc and mica, to form the composition.
The use of a foundation composition which has a significantly high concentration of nacreous material is taught in U.S. Pat. No. 3,978,207. This foundation, a pressed powder composition, is characterized by the presence of a nacreous material such as mica and a binder oil which provides a frosted pearl effect, that is, a lustrous look. The colour of this foundation is provided by the nacreous material.
U.S. Pat. No. 4,659,562 discloses a cosmetic make-up composition which includes, as a binding agent therefore, an intimate mixture of from 5 to 95 weight percent of a mixture of finely divided silica and about 5 to 95 weight percent of finely divided polyethylene fibres. The composition is recited to maintain its uniformity over the areas of the skin to which it is applied. That is, it is said to be "creaseproof". The composition of the '562 patent includes colourant in admixture with nacreous agents.
Nakamura et al., Preprints of the XIVth I.F.S.C.C. Congress, Barcelona, 1986, Vol. I, 51-63 (1986) describes a novel make-up composition utilizing spherical silica and polydimethyl siloxane. This combination is recited to provide a foundation which reduces wrinkle visibility to a greater extent than make-up foundations with which it was compared. This reduction in wrinkle visibility is caused by optical blurring enhanced by the novel use of spherical silica and polydimethyl siloxane.
U.S. Pat. No. 5,143,722 discloses a cosmetic make-up composition comprising water-in-oil emulsions comprising pigment coated with polysiloxane, a silicone phase, a water phase and a polydiorganosiloxane-polyoxyalkylene copolymeric surfactant.
Foundations in the form of water-in-oil emulsions are well known and provide good coverage and good skin feel, wear and appearance. At the same time, it would be desirable to provide a foundation composition having topical anti-acne activity. There are many compounds which are known to exhibit anti-acne properties when applied topically to the skin. A commonly used keratolytic agent having anti-acne activity is salicylic acid. As salicylic acid is virtually insoluble in water it is difficult to incorporate into the aqueous phase of an emulsion composition. Delivery of salicylic acid from the pigment-containing oil phase of an emulsion foundation composition can, however, lead to discolouration of the composition due to interaction between the salicylic acid and pigments, especially of the iron oxide type. It would therefore be desirable to deliver the salicylic acid in soluble form from the aqueous phase.
Polyvinylpyrrolidone is known for use as a solubilizing/complexing agent in a variety of compositions.
GB-A-2,041,963 discloses an aqueous detergent composition for cleansing oily skin comprising a water-soluble salt of an N-acyl ester of sarcosine, a polyvinylpyrrolidone cosolubilizer and a protein and/or protein hydrolysate. The composition can also contain salicylic acid as a keratolytic agent and a buffer such as citric acid/citrate. There is no disclosure, however, of cosmetic compositions containing solubilized acidic anti-acne actives in fully protonated form as specified herein.
Since acidic anti-acne agents are most active at low pH (when a high concentration of free acid is present in solution) it would be desirable to deliver the agent from an aqueous phase at a pH at which it exists significantly in protonated form. It is accordingly a primary object of this invention to provide a cosmetic composition comprising a low pH aqueous solution of an anti-acne active.
It is also an object of the invention to provide a cosmetic composition having improved anti-acne activity and stability.
It is a further object of the invention to provide a cosmetic composition in the form of an oil-in-water or water-in-oil emulsion having improved colour stability and pigment/anti-acne active compatibility.